Which germ layer forms the epidermis of the skin; Endoderm forms epithelium of the digestive tract; Mesoderm forms the serous lining of body cavities?

• A. Ectoderm forms epidermis of skin
• B. Endoderm forms epithelium of digestive tract
• C. Mesoderm forms serous lining of body cavities
• D. Ectoderm- epidermis of skin; Endoderm- epithelium of digestive tract; Mesoderm- the serous lining of body cavities

Answer: (D)

The main idea is where epithelial tissues originate in the embryo. The epidermis comes from the ectoderm, the lining epithelium of the digestive tract comes from the endoderm, and the serous membranes lining the body cavities come from the mesoderm. So a statement that assigns ectoderm to epidermis, endoderm to digestive tract epithelium, and mesoderm to serous lining accurately reflects these established derivations. The other options only capture one or two of these relationships, not all three together.